A cost effective and environmentally sound method to convert heavy hydrocarbon feedstocks to liquid fuel would allow the United States to dramatically expand the use of biofeedstocks and non-conventional hydrocarbon resources, including its vast coal reserves. This would enhance the economic and energy security of the United States by reducing import of energy from foreign sources. However, current methods to convert coal and biofeedstocks to liquid require high temperatures that in turn lead to significant energy consumption and high CO2 emissions.
To realize the potential of unconventional feedstocks in an environmentally sound way, more efficient methods are needed to increase the hydrogen-to-carbon mole ratio (see FIG. 4). Catalysts based on molybdenum disulfide that add hydrogen and remove impurities are widely used in conventional petroleum upgrading, but despite the substantial overlap in process chemistry, they lack sufficient activity and stability in coals and biofeedstocks conversion processes. More stable and active catalysts are needed both as disposable or recyclable particles added to slurries during the liquefaction stage and as shaped catalysts that convert coal and bio-derived liquids to refined products within an ebullating or fixed bed reactor. Currently the best hydrotreating catalysts (not utilizing precious metals) are base metal (e.g., Ni, Co, Mo, W) sulfides deposited onto porous alumina supports of various densities and porosities. Base metal sulfide catalysts are unique because they are insensitive to sulfur poisoning and are active in a wide range of temperatures and H2 pressures.
However, the porous alumina-supported metal sulfide assembly has limited surface area (<250 m2/g), is insulating, and generally requires high temperature for activating the catalyst. Thus, an unmet need exists for an improved porous assembly that has higher surface area, is conductive, has low operating temperature, and enables electrochemical deposition and electrochemical catalysis.